Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to pull even numbers from an array in MongoDB?
Use $mod to get the even numbers and pull them from the array. Let us first create a collection with documents −
>db.pullEvenNumbersDemo.insertOne({"AllNumbers":[101,102,104,106,108,109,110,112,14,17,18,21]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd45b072cba06f46efe9eea")
}Following is the query to display all documents from the collection with the help of find() method −
> db.pullEvenNumbersDemo.find().pretty();
This will produce the following output −
{
"AllNumbers" : [
102,
104,
106,
108,
109,
110,
112,
14,
17,
18,
21
]
}Following is the query to pull even numbers from an array in MongoDB −
> db.pullEvenNumbersDemo.updateMany({},{ "$pull": { "AllNumbers": { "$mod": [ 2, 0 ] } } } );
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }Let us check all the documents once again −
> db.pullEvenNumbersDemo.find().pretty();
This will produce the following output −
{
"_id" : ObjectId("5cd45b072cba06f46efe9eea"),
"AllNumbers" : [
101,
109,
17,
21
]
}
Updated on: 30-Jul-2019
464 Views
Advertisements